141 research outputs found

    Suppression of experimental arthritis through AMP-activated protein kinase activation and autophagy modulation

    Get PDF
    Autophagy plays a central role in various disease processes. However, its contribution to inflammatory arthritides such as rheumatoid arthritis (RA) is unclear. We observed that autophagy is engaged in the K/BxN serum transfer model of RA but autophagic flux is severely impaired. Metformin is an anti-diabetic drug that has been shown to stimulate autophagy. Induction of autophagic flux, through metformin-mediated AMP-activated protein kinase (AMPK) activation and interruption of mammalian target of rapamycin (mTOR) signaling mitigated the inflammation in experimental arthritis. Further investigation into the effects of metformin suggest that the drug directly activates AMPK and dose-dependently suppressed the release of TNF-α, IL-6, and MCP-1 by macrophages while enhancing the release of IL-10 in vitro. In vivo, metformin treatment significantly suppressed clinical arthritis and inflammatory cytokine production. Mechanistic studies suggest that metformin exerts its anti-inflammatory effects by correcting the impaired autophagic flux observed in the K/BxN arthritis model and suppressing NF-κB-mediated signaling through selective degradation of IκB kinase (IKK). These findings establish a central role for autophagy in inflammatory arthritis and argue that autophagy modulators such as metformin may represent potential therapeutic agents for the treatment of RA

    Signal for CP violation in B±PPˉπ±B^{\pm} \to P {\bar P} \pi^{\pm} decays

    Full text link
    We analyze the partial rate asymmetry in B±PPˉπ±B^{\pm} \to P {\bar P} \pi^{\pm} decays (P=π+,K+,π0,η P = \pi^+, K ^+, \pi^0, \eta) which results from the interference of the nonresonant decay amplitude and the resonant amplitude for B±χc0π±B^{\pm} \to \chi_{c0} \pi^{\pm} followed by the decay χc0PPˉ\chi_{c0} \to P {\bar P} . The CP violating phase γ\gamma can be extracted from the measured asymmetry. We find that the partial rate asymmetry for B±π+ππ±B^\pm \to \pi^+ \pi^- \pi^\pm is 0.33 sinγ0.33~sin \gamma, while for B±K+Kπ±B^\pm \to K^+ K^-\pi^\pm it amounts 0.45 sinγ0.45~ sin \gamma.Comment: 3 pages, latex, no figures, Talk given by S. Fajfer at the Hyperons, Charm and Beauty Hadrons, Genova, Italy, 30 June -3 July 1998, to appear as proceedings in Nucl. Phys.

    B -> K1 gamma and tests of factorization for two-body non leptonic Bdecays with axial-vector mesons

    Full text link
    The large branching ratio for B-> K1 gamma recently measured at Belle implies a large B -> K1 transition form factor and large branching ratios for non leptonic B decays involving an axial-vector meson. In this paper we present an analysis of two-body B decays with an axial-vector meson in the final state using naive factorization and the B -> K1 form factors obtained from the measured radiative decays. We find that the predicted B -> J/psi K1 branching ratio is in agreement with experiment. We also suggest that the decay rates of B -> K1 pi, B -> a1 K and B -> b1 K could be used to test the factorization ansatz.Comment: 8 pages; 7 new references included and a comment on K2(1430) in the final state adde

    FACTORS AFFECTING ECOTOURISM LOYALTY WITH THE MODERATING ROLE OF SOCIAL INFLUENCE - EMPIRICAL EVIDENCE IN VIETNAM

    Get PDF
    Today, ecotourism has become more common and attractive for tourists who love to explore nature and experience the cultural heritage. In the 4.0 age of technology, social networking not only helps visitors find suitable destinations to visit easily but also provides visitors with a place to leave comments or reviews after the trips. This study aims to qualify the relationships between electronic-worth-of-mouth (eWOM), social influence (SI), destination image (DI), tourist satisfaction (SAT), and ecotourism loyalty (EL). The study applied the PLS-SEM model to estimate 499 observations at ecotourism sites in Vietnam as empirical evidence. The research results show that all the factors in the research model have positive and significant effects on EL. In particular, DI and SAT, directly and indirectly, affect EL; while eWOM and SI only have direct effects on EL. Additionally, it was found that the effect of eWOM on EL increased with the moderating role of SI

    B => \pi \pi \ell \nu decays in a QCD relativistic potential model

    Full text link
    In the framework of a QCD relativistic potential model we evaluate the form factors describing the exclusive decay B => \pi\pi \ell \nu. The calculation is performed in a phase space region far away from the resonances and therefore is complementary to other decay mechanisms where the pions are produced by intermediate particles, e.g. in the chiral approach. We give an estimate of the contribution of the non resonant channel of the order of BR(B- => \pi+ \pi- \ell \nu) \approx 2.2 x 10^(-4).Comment: 14 pages LaTeX2e + 3 figures, Napoli Preprint DSF 99/3

    Final State Interactions in B>DρB -> D \rho and B>DπB -> D^{*}\pi Decays

    Full text link
    We analyze final state strong interaction effects in B>DρB -> D \rho and B>DπB -> D^{*}\pi decays using the Regge model. We find that, due to the smallness of the contributions from the non-leading Regge trajectories (ρ\rho, ff, π\pi etc.), final state interaction phases are small if the Pomeron coupling to the charm quark is suppressed in comparison to lighter quarks. Our conclusion is that for BB decays into states containing charm, final state interaction effects should play a minor role.Comment: 10 pages, LaTeX, accepted for Physics Letters

    Pantoea stewartii subsp. stewartii, the causative agent of Thai jackfruit’s bronzing disease and its possible host range in Vietnam

    Get PDF
    The bronzing disease of Thai jackfruit (Artocarpus heterophyllus Lam.) has recently appeared in Vietnam, causing a significant loss for farmers, but its control method is still restricted. In this study, we identified pathogens based on morphological and molecular characterizations. A total of 25 bacterial isolates were isolated from diseased samples. The bacterium produces white or yellow pigment in culture, is gram-negative, slightly pleomorphic, non-motile, facultatively anaerobic, short-rod, and catalase-positive. It hydrolyzes gelatin and starch but not tween 80, and produces acid from glucose, sucrose, and lactose. The bacterium does not produce indole and does not produce hypersensitivity to tobacco. The results of sequencing of the encoded region of synthesis of capsular polysaccharide (cpsD) and pathogenicity-related genes HrpS confirmed that the causative agent is Pantoea stewartii subsp. stewartii. The pathogen’s possible host range could be traditional jackfruit varieties, fruits, and crops such as durian, longan, mango, tomatoes, broccoli, pumpkin, cucumber, corn, rice, sweet potatoes, water spinach, peanuts, and green beans. The P. stewartii subsp. stewartii could enter the host plant cell through open wounds or natural openings such as stomata. The results confirmed the presence of P. stewartii subsp. stewartii in Vietnam and suggest that the jackfruit tree should not be planted in plantations with these crops to prevent cross-contamination and the spread of pathogens

    Neutrinos in 5D SO(10) Unification

    Full text link
    We study neutrino physics in a 5D supersymmetric SO(10) GUT. We analyze several different choices for realizing the See-Saw mechanism. We find that the "natural" scale for the Majorana mass of right-handed neutrinos depends critically on whether the right-handed neutrinos are located in the bulk or localized on a brane. In the former case, the effective Majorana mass is "naturally" of order the compactification scale, about 10^{14} GeV. Note, this is the value necessary for obtaining a light tau neutrino mass approximately 10^{-2} eV which, within the context of hierarchical neutrino masses, is the right order of magnitude to explain atmospheric neutrino oscillations. On the other-hand when the right-handed neutrino is localized on the brane, the effective Majorana mass is typically larger than the compactification scale. Nevertheless with small parameters of order 1/10 - 1/30, an effective Majorana mass of order 10^{14} GeV can be accommodated. We also discuss the constraints on model building resulting from the different scenarios for locating the right-handed neutrinos.Comment: 24 page
    corecore